It is known that glucagon is a peptide hormone consisting of 29 amino acids and regulates glycometabolism by acting in coordination with insulin. However, there are not many reports regarding its pharmacokinetics. The glucagon described in these reports are of animal pancreatic origin, but a glucagon by utilization of genetical engineering technique by the use of yeast fungus has been developed recently.
We have made an assessment this time regarding the safety and pharmacokinetics in man of the glucagon (GL-G) by genetical engineering by administering it subcutaneously and intravenously in a single dose (1mg) each to ten Japanese healthy volunteers as subjects (age 20-25, average 22).
The results were as follows:
1) No subjective symptom, abnormal clinical laboratory value or abnormal physiological test result ascribable to GL-G administration or found problematic in the clinical aspect was observed.
2) The findings obtained regarding the blood glucagon concentration (IRG) by subcutaneous administration were: Tmax-8.0±1.1min(mean±SE); Cmax-6, 629±476pg/ml; AUC-4, 710±301pg·hr/ml; and T1/2-19.9±1.5min. The findings by intravenous administration turned out to be T1/2-3.1±0.2min and AUC-6, 394±937pg·hr/ml, the latter being about 1.4 times as large as that by subcutaneous administration.
3) The in vivo pharmacokinetics of BS, IRI, CPR and GH agreed well with the glucagon of animal pancreatic origin, from which it was assumed that the glucagon has the same physiological activity.
From the above, it has been concluded that GL-G poses no problem regarding its safety within the range of the dosage used in present test and is a preparation with the possibility of clinical application in future.
